Thermal flowmeters work on the principle of proportionality of heat transferred material from one point to another, the mass flow rate of the substance. Figure 1.a, and shows how the two temperature transmitters (IPT) determine the temperature of the substance before and after heating, which is a heating element located between the transducers.

Hot wire measures the flow rate of matter using a single heating element located in its flow (Fig. 1.b). The cooling effect of flowing through the element of matter characterized by mass flow, ie cooling is indicated by changing the resistance wire heating element. Often, instead of a wire element in the drive uses a metal foil. With the hot-wire anemometer can measure extremely fast flow fluctuations of matter.

In practice, we know quite a lot of methods to determine the flow rate. The simplest and therefore the most common of these are methods of using mechanical sensors, in which the flow moves or turns solid. Thus, this movement or rotation of the body is proportional to the flow rate. ...